NOT FINISHED YET!!! My first try to get a self built fully working Quadrocopter based on an mbed, a self built frame and some other more or less cheap parts.

Dependencies:   mbed MODI2C

Sensors/Gyro/L3G4200D.cpp

Committer:
maetugr
Date:
2012-10-31
Revision:
17:e096e85f6c36
Parent:
16:74a6531350b5
Child:
20:e116e596e540

File content as of revision 17:e096e85f6c36:

#include "L3G4200D.h"

L3G4200D::L3G4200D(PinName sda, PinName scl) : I2C_Sensor(sda, scl, L3G4200D_I2C_ADDRESS)
{
    // Turns on the L3G4200D's gyro and places it in normal mode.
    // Normal power mode, all axes enabled (for detailed info see datasheet)
    
    //writeRegister(L3G4200D_CTRL_REG2, 0x05);               // control filter
    writeRegister(L3G4200D_CTRL_REG2, 0x00);            // highpass filter disabled
    writeRegister(L3G4200D_CTRL_REG3, 0x00);
    writeRegister(L3G4200D_CTRL_REG4, 0x20);            // sets acuracy to 2000 dps (degree per second)
    
    writeRegister(L3G4200D_REFERENCE, 0x00);
    //writeRegister(L3G4200D_STATUS_REG, 0x0F);
    
    writeRegister(L3G4200D_INT1_THS_XH, 0x2C); // TODO: WTF??
    writeRegister(L3G4200D_INT1_THS_XL, 0xA4);
    writeRegister(L3G4200D_INT1_THS_YH, 0x2C);
    writeRegister(L3G4200D_INT1_THS_YL, 0xA4);
    writeRegister(L3G4200D_INT1_THS_ZH, 0x2C);
    writeRegister(L3G4200D_INT1_THS_ZL, 0xA4);
    //writeRegister(L3G4200D_INT1_DURATION, 0x00);
    
    writeRegister(L3G4200D_CTRL_REG5, 0x00);            // deactivates the filters (only use one of these options)
    //writeRegister(L3G4200D_CTRL_REG5, 0x12);          // activates both high and low pass filters
    //writeRegister(L3G4200D_CTRL_REG5, 0x01);          // activates high pass filter
    
    writeRegister(L3G4200D_CTRL_REG1, 0x0F);            // starts Gyro measurement
    
    // calibrate gyro with an average of count samples (result of calibration stored in offset[])
    for (int j = 0; j < 3; j++)
            offset[j] = 0;
            
    float Gyro_calib[3] = {0,0,0};                      // temporary var for the sum of calibration measurement
    
    const int count = 50;
    for (int i = 0; i < count; i++) {                   // read 50 times the data in a very short time
        read();
        for (int j = 0; j < 3; j++)
            Gyro_calib[j] += data[j];
        wait(0.001);          // TODO: maybe less or no wait !!
    }
    
    for (int j = 0; j < 3; j++)
        offset[j] = Gyro_calib[j]/count;                // take the average of the calibration measurements
}

void L3G4200D::read()
{
    char buffer[6];                                     // 8-Bit pieces of axis data
    
    //buffer[0] = L3G4200D_OUT_X_L | (1 << 7);          // TODO: wiiiiiiso?!
    
    readMultiRegister(L3G4200D_OUT_X_L | (1 << 7), buffer, 6); // read axis registers using I2C
    
    data[0] = (short) (buffer[1] << 8 | buffer[0]);     // join 8-Bit pieces to 16-bit short integers
    data[1] = (short) (buffer[3] << 8 | buffer[2]);
    data[2] = (short) (buffer[5] << 8 | buffer[4]);
    
    for (int j = 0; j < 3; j++)
            data[j] -= offset[j];                       // add offset from calibration
}

int L3G4200D::readTemp()
{
    return (short) readRegister(L3G4200D_OUT_TEMP);     // read the sensors register for the temperature
}